A prevention of diseases of poultry flocks is one of the prerequisites for ensuring good health and high yield of housed animals as well as achievement of economic profit. Many diseases of poultry can be avoided by using good animal breeding practices as well as introduction of the management of the health status of the entire flock. The main focus of our work was to create a complex of preventive possibilities to minimise the potential disease-causing mi­croorganisms in all steps of poultry breeding. That is based on the principle of timing. It starts in a hatchery through the rearing chickens to the broilers or egg laying flocks with emphasis on an animal health and a quality of produc­tion.